Shampoo brush



FIG. 1 is a front perspective view of a shampoo brush showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof; and,

FIG. 6 is a right side view thereof, the left side being a mirror image thereof. 

The ornamental design for shampoo brush, as shown and described. 